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  <div class="section" id="mathematical-functions-with-automatic-domain-numpy-emath">
<h1>Mathematical functions with automatic domain (<code class="xref py py-mod docutils literal notranslate"><span class="pre">numpy.emath</span></code>)<a class="headerlink" href="#mathematical-functions-with-automatic-domain-numpy-emath" title="Permalink to this headline">¶</a></h1>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p><code class="xref py py-mod docutils literal notranslate"><span class="pre">numpy.emath</span></code> is a preferred alias for <a class="reference internal" href="#module-numpy.lib.scimath" title="numpy.lib.scimath"><code class="xref py py-mod docutils literal notranslate"><span class="pre">numpy.lib.scimath</span></code></a>,
available after <a class="reference internal" href="index.html#module-numpy" title="numpy"><code class="xref py py-mod docutils literal notranslate"><span class="pre">numpy</span></code></a> is imported.</p>
</div>
<span class="target" id="module-numpy.lib.scimath"></span><p>Wrapper functions to more user-friendly calling of certain math functions
whose output data-type is different than the input data-type in certain
domains of the input.</p>
<p>For example, for functions like <code class="xref py py-obj docutils literal notranslate"><span class="pre">log</span></code> with branch cuts, the versions in this
module provide the mathematically valid answers in the complex plane:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">math</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">numpy.lib</span> <span class="kn">import</span> <span class="n">scimath</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">scimath</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="o">-</span><span class="n">math</span><span class="o">.</span><span class="n">exp</span><span class="p">(</span><span class="mi">1</span><span class="p">))</span> <span class="o">==</span> <span class="p">(</span><span class="mi">1</span><span class="o">+</span><span class="mi">1</span><span class="n">j</span><span class="o">*</span><span class="n">math</span><span class="o">.</span><span class="n">pi</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Similarly, <code class="xref py py-obj docutils literal notranslate"><span class="pre">sqrt</span></code>, other base logarithms, <code class="xref py py-obj docutils literal notranslate"><span class="pre">power</span></code> and trig functions are
correctly handled.  See their respective docstrings for specific examples.</p>
</div>


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